1. Field of the Invention
The present invention relates to a panel operator structure for electronic equipment such as sound equipment.
2. Description of the Related Art
Conventionally, some electronic equipment such as sound equipment includes an operation panel provided with a number of operator units. An operation panel of this type has a base plate thereof mounted with various switches that are each adapted to be turned on/off for function settings of the electronic equipment when a corresponding one of the operator units is operated.
FIG. 6 is an exploded schematic view showing an example of a prior art panel operator structure for electronic equipment, and FIG. 7 is a vertical section view of an operator unit of the prior art panel operator structure.
As shown in FIGS. 6 and 7, the panel operator structure includes a number of operator units (only one of which is shown by reference numeral 130 for simplified illustration) fixed on a base plate 120 and an operation panel 110 disposed in an overlapping relation and parallel with the base plate 120.
The base plate 120 has its four corners where there are formed an alignment hole 121, an elongated hole 124, and unloaded holes 122 and 123, which are used for panel mounting. Furthermore, three operator unit mounting holes 126 and two operator unit locating holes 127 are formed in the base plate 120, and switches (only one of which is shown at 125) are disposed on the base plate 120.
As shown in FIG. 7, the operator unit 130 includes a casing 132 to which a key top 131 as a depression-operated portion is connected via a hinge 135. An actuator 136 is formed integrally with a lower portion, as seen in FIG. 7, of the key top 131. The key top 131 is, when depressed or released, pivoted relative to the casing 132 in the vertical direction in FIG. 7. The switch 125 is turned on when depressed by the actuator 136.
The operator unit 130 is formed with three mounting pawls 133 and two locating pins 134 and fixed in position to the base plate 120 by the pawls 133 and the locating pins 134 inserted into the operator unit mounting holes 126 and the operator unit locating holes 127 of the base plate 120 for engagement therewith.
The operation panel 110 has its four corners formed with studs 111 in each of which a self-tapping pilot hole, not shown, is formed. To fix the operation panel 110 to the base plate 120, screws 128 are threadedly engaged with the self-tapping pilot holes of the studs 111 from the rear side of the base plate 120, with the studs 111 of the operation panel 110 aligned with the alignment hole 121, the elongated hole 124, and the unloaded holes 122, 123 and abutted against the base plate 120 on which the operator unit 130 has been mounted.
The operation panel 110 is formed with operator unit insertion holes 112 into which the operator units 130 are inserted. In a state where the operation panel 110 is fixed to the base plate 120, the key top 131 of each operator unit 130 is disposed within the insertion hole 112 with a clearance therebetween, as shown in FIG. 7. Provided that the operator unit 130 is disposed in position within the insertion hole 112, the key top 131 is kept out of contact with the insertion hole 112 when depressed or released.
In the prior art panel operator structure shown in FIGS. 6 and 7, the horizontal positional relation between the operation panel 110 and the base plate 120 is determined by the positional relation between the alignment hole 121 and a corresponding one of the pilot holes of the studs 111.
In the case of the operation panel 110 made of metal, the studs 111 are ordinarily welded or the like to the operation panel 110, and weld positions of the studs 111 can vary. In addition to a variation in the weld positions of the studs 111, there can be variations in shape of the studs 111 and position and shape of the pilot holes, resulting in a deviation in the positions of the studs 111 on the operation panel 110, which causes a deviation in the positional relation between the operation panel 110 and the base plate 120.
The horizontal positional relation between the operator units 130 and the operator unit insertion holes 112 of the operation panel 110 is affected not only by the above-described positional deviation between the operation panel 110 and the base plate 120, but also by the mounting accuracy of the operator units 130 on the base plate 120 since, as described above, the operator units 130 are fixed on the base plate 120. Furthermore, the positional relation between the operator units 130 and the insertion holes 112 is affected by the accuracy of formation of the insertion holes 112 in the operation panel 110.
Thus, a proper positional relation between the operator units 130 and the operator unit insertion holes 112 cannot sometimes be attained. In that case, the clearance between the insertion hole 112 and the key top 131 increases on one side of the key top, but decreases on the other side thereof. As a result, the key top 131 can be in contact with the insertion hole 112 when depressed or released. Such contact can result in operation failure, degraded operation feeling or the like.
For EMI countermeasure, rigidity maintenance, reduction in die cost or the like, a large-sized mixer apparatus in particular is often demanded to be made of metal (a steel plate or the like), not of resin. Moreover, such a mixer apparatus or the like is provided with a number of operator units 130. Therefore, the operation panel 110 becomes large in size, and a number of operator unit insertion holes 112 must be formed. The accuracy of forming the insertion holes 112 in the operation panel 110 is liable to be worsened. As a result, it is further difficult to attain a proper positional relation between the operator units 130 and the operator unit insertion holes 112 and between the operator panel 110 and a base plate 120.
Conventionally, therefore, the operation panel and the base plate formed with no locating holes are sometimes positioned by a personnel based on a visual checking to have a proper positional relation to each other. Then, the operation panel is fixed to the base plate by the personnel. However, such work is cumbersome.
Pattern wiring inhibition regions where formation of wiring patterns is inhibited are provided in the vicinity of operator unit mounting holes formed in the base plate. Thus, the greater the number of the operator units that must be provided, the much worsened the efficiency of pattern wiring will be.
Meanwhile, in the case of an operation panel made of resin as disclosed in Japanese Laid-open Patent Publication No. 06-267373, protrusions or other mounting portions can be formed on the operation panel, whereby operator units can be fixed to the operation panel.
On the other hand, in a case where such mounting portions are provided by welding or the like to an operation panel made of metal, the accuracy of providing the mounting portions becomes low, and therefore, a proper clearance cannot sometimes be provided between operator unit insertion holes and key tops, which poses a problem.